Liquid level indicating means



P 1943- F.-P. SCULLY Er/u 2,328,686

LIQUID LEVEL INDIdATING' MEANS Filed Feb. 2; 1939 INVENTOR Hank RScully BY Alcide E JVafl-zgy 7 ATTogEY Patented Sept. 7, 1943 LIQUID LEVEL INDICATIN G MEANS Frank P. Scully, Cambridge, and Alcide E. Mathey, Auburndale, Masa, assignors to Scully Signal 00., East Cambridge, Mass., a corporation of Massachusetts Application February 2,1939, Serial No. 254,294

Claims. (Cl. 137-111) The invention relates to the provision of means for indicating the level of liquid in tanks.

As is well known, in filling tanks it is ordinarily desirable to fill the tank as full as possible with-' out overflowing. It is one of the objects of this invention to provide means which will indicate to the operator when the filling has proceeded to a point very close to the top of the tank so that the supply may then be terminated before overflowing takes place.

This invention is particularly adapted for use with small tanks of the size used, for example, on automobiles, where absence of indicating means often results in overflowing.

The construction that we use to advise when filling has been completed includes a whistle capable of giving a suificiently loud sound to be readily heard by the operator. The whistle is positioned in the path of venting gases and so constructed that adequate venting capacity will always be available regardless of the rate of fill and the degree to which the tank has been filled.

Other objects and accomplishments of our invention will become more apparent as the description proceeds with the aid of the accompanying drawing in which:

' Fig. 1 shows a tank having filling and venting connections;

Fig. 2 shows one form of audible signalling device that may be used in which the whistling is affected by a change in the nature of the air stream passing through the whistle;

Figs. 3 and 4 show another form of audible signalling device in which the whistling is changed through modification of the whistle structure;

Fig. 5 shows still another form of signalling device in which auxiliary venting means is provided;

Fig. 6 isanother modification in which the auxiliary venting means is remote from the si nalling device;

will not be vented back through the fill pipe but rather through the other venting means provided. Typical constructions which may be used to prohibit venting back through the fill pipe are the provision of a tight connection at the filler neck between the fluid supply line and the fill pipe,

provisionof a change in direction of the filler pipe so that the entering liquid will completely fill the pipe at that point, thereby preventing escape of gases, and the provision of a deep fill which is indicated in Fig. l.

The vent pipe 6 may likewise be positioned at any convenient point on the upper portion of the Fig. I shows still another modification with tank and provides means through which gas displaced by the entering liquid may escape.

For convenience in applyingour invention, a housing 8 is provided under which is positioned the audible signallingdevice that will hereinafter be described.

One form of our invention is shown in Fig. 2, in which there is a whistle ill of the hollow button type, usually cylindrical in plan, which is secured in place in a. corresponding opening in the top of tank 2. Whistle ID has centrally located holes l2 and M which cause a distinct whistling sound when gas is passed therethrough. Whistles of this construction require very little pressure for satisfactory operation, and the pressure developed in the ordinary filling of a tank is adequate for good audibility.

It is apparent that with the whistle structure of Fig. 2 whistling will proceed as the tank is being filled. In order to indicate to the operator when the filling has been completed, we provide a float I6 which may be of cork or other buoyant material or in the form of a hollow member, all of which are adapted to rise under the influence or the mounting liquid level.

The fioat I6 maybe guided in any convenient manner. In the form shown we have provided a frame l8 which may depend from whistle Ill as shown or from the tank if desired. Frame l8 carries the vertical member 20 which extends through a vertical centrally located hole in float Hi. The guide means, however, is only illustrative, and we contemplate that in this form of our invention and in all of the other forms shown the guide means for the various floats may be of any convenient structure.

As the fillingproceeds it is apparent that float J6 will ascend to the dotted line position indicated, and at that point the upper end of the float will be close to the hole M of whistle I0, but will be prevented from reaching and closing the whistie apertures because of stop 22 on the upper end of guide 20. Float l6, however, approaches so closely to whistle III that the direction of gas entering and passing through the whistle is so altered and distorted that the resonance is destroyed, with the result that whistling ceases. It should be understood, however, that float I6 is not permitted to interfere with the Venting capacity of the whistle even though the air stream is altered, for the reason that the effective area. between float I6 and the whistle is not reduced below the area of the holes l2 and I4.

Thus, when float 16 has risen to the upper position shown and the whistling has ceased, the operator will be advised that the tank is full.

Figs. 3 and 4 illustrate other modifications of our construction in which the whistle is fixed integrally with the tank as in the case of Fig. 2. In Fig. 3 the whistling proceeds while the tank is being filled, stopping when the float I6 is raised by the liquid; whereas in Fig. 4 the whistle is silent while filling takes place but commences to whistle when the float has been raised from the dotted line position to the solid line position.

In both forms, however, the principle of operation is the same and utilizes the principle of varying the physical characteristics of the whistle itself to alter the resonance of the device.

In Fig. 3 whistle I is secured in a corresponding opening in the top of tank 2 and has the usual A upper and lower holes l2 and i4 therethrough.

In addition, however, is another aperture 24 which in the case of Fig. 3 is normally closed by a valve member 26 having a depending stem 28 passing through a closely fitting hole 30 in the lower side of the whistle and having on its lower end a float I6. To assist in the operation of this device, guide means 32 is provided, shown diagrammatically in the drawing, but which may take any convenient mechanical form.

As the filling of the tank proceeds, the venting gases will escape through holes l2 and 14 of the whistle so that an audible sound will be heard by the operator. When the liquid level rises sufflciently so that float I6 is moved upwardly to the dotted line position, valve 26 will be raised to open port 24, thus changing the venting area on the top side of the whistle. This results in destroying the effectiveness of the whistle so that the gas passing therethrough no longer produces I When, however, the rising liquid level moves float l6 upwardly so that valve 26 .closes port 24, the gas vented thereafter must pass .through holes l2 and i4 only, with the result that the whistling sound is created and the operator is thus advised that the tank is full.

The constructions shown in Figs. 5, 6, 7 and 8 diflerfrom those shown in Figs. 2, 3 and 4 in that auxiliary venting means apart from the whistle itself is provided. It will be noted in Figs. 2, 3 and 4 that the escaping gas must pass through apertures in the whistle itself; whereas in Figs. 5, 6, 'l and 8 escaping gas may pass not only through the whistle but also through other ports if the pressure in the tank becomes sufflcient to warrant auxiliary venting.

-- the tank is full.

In Fig. 5 the whistle and float construction is the same as that shown in Fig. 2 with this dinerence-that the whistle, instead 0! being secured to the tank in a corresponding opening in the top, merely rests on the top of the tank. The periphcry of the hole through the tank forms a seat 34 on which the outer circumferential portion of the whistle I0 is supported.

It is believed apparent that if, during fllling, the pressure in the tank should become excessive, whistle l0 would be blown upwardly off seat 34,

thereby increasing the effective venting area to the degree necessary to provide free venting. The housing 8 limits excessive upward movement of whistle l0. Apart from this distinction, however, the operation of the construction of Fig. 5 is much like that of Fig. 2. However, no stop is provided on the upper end of guide 20, so that when filling has been completed, float I6 will close the whistle orifices, thereby compelling further escape of gas between seat 34 and whistle i0. As the liquid level rises, moving float l6 upwardly with it, it is apparent that before the whistle orifices are actually closed the float will first approach the whistle closely enough to distort the gas stream passing through the orifices, and thereafter, as the level rises still further, the orifices will be finally closed. Whistling ceases as soon as the float has risen to that point at which the gas streamis sufiiciently distorted, and, of course, there can be no whistling when the orifices are shut ofif. In this manner the desired indication is given to the operator.

In Fig. 6 another construction is shown in which the auxiliary venting means is apart from the whistle itself. In this form whistle I8 is secured in a suitable aperture in the top of tank 2 the same as in the constructions of Figs. 2, 3 and 4. The auxiliary venting means is provided by a series of holes 36 extending circumferentially through the tank top and about whistle l0. Holes 36 are normally closed by an annular valve member 38. If the pressure in the tank becomes excessive so that orifices l2 and I4 are inadequate, the gas pressure through holes 36 will cause valve 38 to lift, thereby providing additional venting capacity. Excessive upward movement of valve 38 is prevented by housing 8.

The whistling in the construction of Fig. 6 is controlled in the same manner as in Fig. 5. Float I6 is guided by member 20 so that as the liquid level rises, the orifices through the whistle ill will finally be closed, causing cessation of the whistling sound, indicating to the operator that Further escape of gas thereafter is provided for by means of holes 36 and pressure-operated valve 38.

The construction of Fig. 7 is a modification of that shown in Fig. 6. Instead of providing a series of holes covered by an annular valve, we have here provided a single larger hole 40 normally closed by a ball valve 42. When the pressure caused by escaping gas becomes excessive or when the holes l2 and I4 of whistle ill have been closed by the rising of float N5, gas may escape through the auxiliary port 40, the pressure dislodging valve 42 from its seat. Excessive movement of the valve 42 is prevented by the guide member 44 and the housing 8.

The operation of float I6 in the construction of Fig. 7. is the same as that in Figs. 5 and 6 in that the float rises under the influence of the rising liquid level first to distort the gas stream passing through the orifices and finally to close the orifices through the whistle. Whistling will I 2,828,686 cease when-the gas stream is sufficiently distorted.

or the orifices closed, thereby-giving the desired indication to the operator;

The construction shown in Fig. 8 is still a fur- 'ther modification in which the reverse whistling action takes place the same as caused by the construction shown in Fig. 4. During the filling operation the whistle is silent, but when the tank is filled, whistling commences.

In this construction whistle i rests on seat 34 of tank 2, and the ports l2 and I4 are normally closed by valve 46 whichhas depending therefrom a valve stem 48 extending through holes l2 and i4 and on the lower end of which is a. float l6. Guide means 50 may be provided so that float l6 and valve stem 48 may be constrained to move in a vertical direction. In the form shown, guide means 50 is connected to whistle ill, but if desired, the guide means may be connected with the underside of the top of tank 2. During the filling operation, as the gases-cannot pass through the orifices of the whistle, they are permitted to escape through the area created between the whistle l0 and seat 34' when the whistle is moved upwardly by the gas pressure.

When, however, the liquid level rises to a point sufiicient to move float i6 upwardly, valve 46 will be moved away from the opening l2 ofthe whistle; and when this movement has advanced sufficiently, the gases escaping through the orifices i2 and I4 of the whistle will produce a whistling sound to notify the operator that the tank is full. The whistling will be produced even though some of the gas, in the case where the pressure is excessive, may be escaping between the valve and seat 34.

In the forms shown in Figs. .5, 6 and 7, fioat stops, as 22 in Fig. 2, may be provided to prevent complete closing of the whistle orifices, but at the same time permitting the float or float-operated means to approach the whistle sufilciently to cause cessation of whistling without cutting of! the venting capacity. y

In all of the constructions shown and described lt'is apparent that the whistling is created or stopp d by changing the character of the gas stream passing through the whistle rather than through any movement of the whistle itself. In some cases the direction of the entering air stream is altered but not cut off. In other cases the gas passing through the whistle is cut off altogether; and in other cases the gases passing through the whistle are diversified through the creation or elimination of orifice area in the whistle itself. In those cases where no auxiliary venting means is provided,.it will be noted that the orifices in the whistle are never sealed so that .a dangerous pressure condition within the tank cannot be created. In those cases where the orifices through the whistle are sealed, auxiliary venting means is provided which again prevents the creation of dangerously excessive pressures.

In all cases it is apparent that we have PIO- vided means which extends downwardly into thetank a very short distance, and that the change in the audible signal is not brought about until the tank is substantally full. This is a particularly desirable feature as it permits quick filling to a degree heretofore 'unobtainable without danger of overflowing.

In the constructions shown, the float itself has acted to close or modify theventing orifices, but it should be understood that other means operated by the float could be arranged to aocomplish the same results.

While we have shown and described a number of modifications of our invention, we wish it to be understood that we do not intend to be limited thereby but only-by the appended claims. 1

We claim:

1. In combination, a tank having filling and venting means, a gas-operated, sound-producing device positioned in the path of gases escaping from the tank, said sound producing device having a plurality of ports, float-operated means for varying the combined area of said ports without restricting the venting capacity below a predetermined limit, whereby the audibility or said device may be varied while gases are passing therethrough.

2. The combination with a tank for liquid having a vent passage with a valve seat formed ,therein, Of an air operated signal connected to tank for liquid, comprising a venting connection for said tank, a whistle normally open and positioned in said venting connection in fixed relation to said tank in the path of venting gases whereby said whistle will produce an audible sound during normal filling of said tank, a by-pass in said venting connection, a valve normally closing said by-pass, buoyant means connected to said valve so that .upon the rising of the liquid level to a predetermined point said buoyant means will be raised to open said by-pass, there rendering said whistle substantially inaudible.

4. An audible signaling device forv use with v a tank, comprising a venting connection. a

; pass, thereby materially altering the sound 7 I whistle permanently fixed in relation to said venting connection and open at all times forthe venting of gas or liquid therethrough, a by-pass normally closed by a valve, 8. float connected to said valve adapted to rise and open said by-pass when the liquid level has risen to a predetermined level whereby part of the venting gas will pass through said whistle and part through said byemanating therefrom.

5. In combination, a tank having a filling port and a vent, said vent including a gas-operated sound-producing device through which gasmay pass, said device having a resonance chamber and a plurality 'ofmassages leading therelnto, said passages so arranged with respect to said resonance chamber that said device may be made audible or inaudible by varying the total area of the passages opening into said resonance cham- 

